Compare the2023 BMW Z4VS 2023 MINI Cooper Convertible

The Z4’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Cooper Convertible doesn’t offer pre-crash pretensioners.

The Z4’s optional blind spot warning system uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. The Cooper Convertible doesn’t offer a system to reveal objects in the driver’s blind spots.

To help make backing out of a parking space safer, the Z4’s optional Cross Traffic Warning uses sensors in the rear to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The Cooper Convertible doesn’t offer a rear cross-path warning system.

Both the Z4 and the Cooper Convertible have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, rearview cameras, driver alert monitors, available lane departure warning systems and rear parking sensors.

There are over 3 times as many BMW dealers as there are MINI dealers, which makes it much easier should you ever need service under the Z4’s warranty.

J.D. Power and Associates’ 2022 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than MINI vehicles. J.D. Power ranks BMW above average in initial quality. With 3 more problems per 100 vehicles, MINI is rated lower.

The Z4 has more powerful engines than the Cooper Convertible:

As tested in Car and Driver the Z4 sDrive30i 2.0 turbo 4-cylinder is faster than the MINI Cooper Convertible turbo 3 cyl. (automatics tested):

On the EPA test cycle the Z4 gets better mileage than the Cooper Convertible:

The Z4 has 2.1 gallons more fuel capacity than the Cooper Convertible (13.7 vs. 11.6 gallons), for longer range between fill-ups.

The BMW Z4 comes standard with an automatic transmission, for driver comfort, especially in the city. Automatic costs extra on the Cooper Convertible.

For better stopping power the Z4’s brake rotors are larger than those on the Cooper Convertible:

The Z4’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the Cooper Convertible are solid, not vented.

The Z4 stops much shorter than the Cooper Convertible:

For better traction, the Z4 has larger standard tires than the Cooper Convertible (F:225/45R18 & R:255/40R18 vs. 195/55R16). The Z4’s optional tires are larger than the largest tires available on the Cooper Convertible (F:255/35R19 & R:275/35R19 vs. 205/40R18).

The Z4’s standard 225/45R18 front and 255/40R18 rear tires provide better handling because they have a lower 45 series front and 40 series rear profile (height to width ratio) that provides a stiffer sidewall than the Cooper Convertible’s standard 55 series tires. The Z4’s optional tires have a lower 35 series profile than the Cooper Convertible’s optional 40 series tires.

For better ride, handling and brake cooling the Z4 has standard 18-inch wheels. Smaller 16-inch wheels are standard on the Cooper Convertible. The Z4’s optional 19-inch wheels are larger than the 18-inch wheels optional on the Cooper Convertible.

For better handling and stability, the average track (width between the wheels) on the Z4 is 4.6 inches wider in the front and 4.4 inches wider in the rear than the average track on the Cooper Convertible.

The Z4’s front to rear weight distribution is more even (51.2% to 48.8%) than the Cooper Convertible’s (61.9% to 38.1%). This gives the Z4 more stable handling and braking.

The Z4 M40i handles at 1.02 G’s, while the Cooper Convertible pulls only .84 G’s of cornering force in a Car and Driver skidpad test.

The design of the BMW Z4 amounts to more than styling. The Z4 offers aerodynamic coefficients of drag from .29 to .31 Cd (depending on bodystyle and options). That is significantly lower than the Cooper Convertible (.36 to .37) and many sports cars. A more efficient exterior helps keep the interior quieter and helps the Z4 get better fuel mileage.

As tested by Car and Driver while cruising at 70 MPH, the interior of the Z4 sDrive30i is quieter than the Cooper Convertible S (70 vs. 71 dB).

The Z4 has .8 inches more front legroom and 3.3 inches more front shoulder room than the Cooper Convertible.

The Z4 has a much larger trunk with its top down than the Cooper Convertible with its top down (9.9 vs. 5.7 cubic feet). The Z4 has a much larger trunk than the Cooper Convertible with its top up (9.9 vs. 7.6 cubic feet).

A low lift-over trunk design makes loading and unloading the Z4 easier. The Z4’s trunk lift-over height is 28.5 inches, while the Cooper Convertible’s liftover is 31.5 inches.

With its convertible body style, valet key and remote trunk release lockout, the Z4 offers cargo security. The Cooper Convertible’s non-lockable remote release defeats cargo security.

The engine in the Z4 is mounted longitudinally (North-South), instead of sideways, as in the Cooper Convertible. This makes it easier to service and maintain, because the accessory belts are in front.

The Z4 offers a remote vehicle starting system, so the vehicle can be started from inside the driver's house. This allows the driver to comfortably warm up the engine before going out to the vehicle. The climate system will also automatically heat or cool the interior. The Cooper Convertible doesn’t offer a remote starting system.

When two different drivers share the Z4, the memory system makes it convenient for both. Each setting activates different, customized memories for the driver and front passenger’s seat positions, outside mirror angle, climate settings and radio stations. The Cooper Convertible doesn’t offer a memory system.

The Z4’s power parking brake sets with one touch and releases with one touch or automatically. The Cooper Convertible has a lever-type parking brake that has to be strenuously raised to engage properly. It has to be lifted up more and a button depressed to release it.

The Cooper Convertible’s optional cornering lamps activate a lamp on the front corner when the turn signal is activated. The Z4’s optional adaptive cornering lights turn the actual headlight unit up to several degrees, depending on steering wheel angle and vehicle speed. This lights a significant distance into corners at any speed.

The Z4 has a standard dual zone air conditioning allows the driver and front passenger to choose two completely different temperatures so people with different temperature preferences won’t have to compromise. This makes both the driver and front passenger as comfortable as possible. Dual zone air conditioning is only available on the Cooper Convertible Signature/Iconic.

Consumer Reports® recommends both the BMW Z4 and the MINI Cooper Convertible, based on reliability, safety and performance.